Stove or furnace



April 17, 1934. VE. F. EICHHORN STOVE`OR FURNACE Filed Oct. 20, 1930 2 Sheets-Sheet l ZM Il,

lApril 17, 1934.

E. F, EICHHORN ST'OVE OR FURNACE Filed OCb. 20, 1930 2 Sheets-Sheet 2 Patented Apr. 17, 1934 UNITED STATES PirrsN'r oFFics 7 Claims.

This invention relates to certain improvements in stoves or furnaces and has for its primary object to provide improved means in a down draft type of heating device so as to acquire a maximum heat from fuel such as coal combusted.

Another object of the invention is to provide a heating device such as a stove or furnace with an improved form of grate bars.

A further object of the invention is in providing a heating device with an improved manner of air entrainment to the combustion chamber.

A still further object of the invention is in providing the heating device with an improved vertically extending air passageway with which the grate bars which are hollow are cooperably connected.

Another still further object of the invention is in providing a heating device with improved means whereby the device can be operated either on a down draft or an open draft system of burng. Other and further objects will appear in the specification and be specifically pointed out in the appended claims, reference being had to the accompanying drawings, exemplifying the invention, and in which:-

Figure 1 is a vertical section taken through a hot air furnace showing the invention thereto.

Figure 2 is a vertical section taken approximate- 3o ly on the line II--Il of Fig. 1.

Figure 3 is a transverse section taken approximately on the line III-III of Fig. 2. Y Figure 4 is an inverted transverse section taken approximately on the line IV-IV of Fig. 2.

Figure 5 is a vertical section taken approximately on the line V-V of Fig. 2.

Referring by numerals to the accompanying drawings 1 designates a vertically disposed hollow member having a front wall 2, rear wall 3 and side walls 4, said hollow member comprising the barrel of the stove or furnace having a top wall 5. The barrel 1 may be of a desired shape in cross section and formed in the front wall 2 is an upper disposed opening 6 providing a coal or lire opening which is under control of the door '7. Formed in the front wall at the lower end of the barrel is an opening 8 for providing access to the ashpit 9 and for closing the opening is an ashpit door 10. Disposed above the ashpit 9 is a shelf 11, said shelf being divided by an intermediately disposed opening 12 which extends approximately from the front wall 2 to the rear wall 3 of the barrel 1 and formed in the front wall 2 on a Y plane with the shelf 11 is a clean out opening 13 which is closed by a door 14.

Disposed intermediately between the lire opening 6 and the clean out opening 13 are a series of horizontal grate bars 15, said grate bars being mounted at one end in respective apertures formed in the front wall 2 of the barrel l and at their opposite ends in respective apertures which are formed in the rear wall 3, said grate bars being hollow and open at their ends, each being provided with a series of apertures 16 which are formed in each side wall 17 of respective grate bars.

Secured to the rear wall 3 is a housing or shell 18, said housing 18 being of the approximate width Vof the wall 3 so as to embrace the rear open ends of the grate bars 15 and formed or -secured to the upper end of the wall 3 is a hori- Zontally disposed defiecting ledge 19, said ledge being disposed a distance from the top 5 kof the barrel 1.

The ledge 19 is of the approximate width of the wall 3 and owing to the housing 18 being secured to the top of the wall 3, said housing and ledge 19 will provide a passageway 20 which leads from the rear hollow ends of the grate bars to the top of the fire pot 21 intermediate of its width and formed inthe top 5 centrally thereof `is an outlet opening 22. Depending from the top 5 of the barrel 1 on a side ofthe opening 22 opposite the ledge 19 is a defiecting portion 23, and mounted over said opening on the top 5 in a. pair of guide members 24 is a slidable damper 25, said damper 25 being located in the smoke box 26 and secured to the damper and extending therefrom is a pull rod 27.

Disposed adjacent each side wall v4 so as to provide a spacing 28 is a series of tubes 30 which lead from the ashpit 9 to the smoke box 26, the spacing 28 providing for air circulation between the tubes 30 and the walls 4 as designated by the arrows 29.

Mounted over the structure is a drum 3l which is secured on one side to the front wall 2 adjacent respective doors 7, 19 and 13 and secured to the smoke box 276 at one end andin communication therewith is a coupling 32 which is extended through the side wall of the drum 31 and connected to the coupling 32 is a flue 33. l

While the disclosures of the drawings is that of a furnace type of heating devioegit is obvious however that the structure can aptly be used as a stove.

In the operation ofthe device, fuel such as coal is deposited in the re pot 21 on to the burning coal bed 34 resting on the grate bars 15, and as the grate bars are hollow and are open ended and j neo in communication with the passageway 20, air will be entrained through the front end 35 of each grate bar, into the passageway 20, over the ledge 19 and downwardly through the coal bed on the grate bars, and downwardly between the bars into the combustion chamber 36 beneath the bars. Obviously, as the air passes through the burning coals aiding the combustion thereof, the air will become heated and upon passing downwardly through the lower combustion chamber 36, the heat will descend through the opening 12 into the ashpit 9 wherein the air currents upon entering the ashpit will divide into two streams, one of which will enter the tubes 30 on one side of the barrel 1 whereas the other diversion of air currents will enter and traverse the opposing tubes 30, the heated air currents after traversing the tubes 30, entering the smoke dome and discharging into the flue 33, this completing the downward draft operation of the heating device.

Inasmuch as the entire structure is enclosed in the drum 31, the burning products of combustion travelling upwardly through the tubes 30 will provide a maximum heat within the drum to be discharged through the usual heat conducting tubes 38 from the drum.

For checking the draft through the furnace, the damper 25 when shifted to a partial open pcsition with respect to the opening 22, will permit some of the air induced in the passageway 25 to discharge through the opening 22 into the smoke box 26 from above the ledge 19. Obviously a maximum checking of the downward travelling air through the re pot 21 and combustion chamber 36 will be given when the damper 25 is entirely withdrawn from the opening 22.

In addition to the air currents travelling through the grate bars 15 to the passageway 20, some of the air induced in the grate bars will pass outwardly through the side disposed apertures 16 where they will mingle with the coal gases passing between the grate bars thereby aiding combustion of the gases and in the event of burning coals dropping between the grate bars, they will be arrested by the shelf 11 and permitted to be consumed thereon. For cleaning purposes, access to the grate bars can be had through clean out opening 37 and access to the shelf 11 for cleaning it can be had through the clean out opening 13. v Y

A stove or furnace of this improved character can also be operated as an up draft by the damper 25 being operated to an open position and permitting air to be entrained into the ashpit 9 to the ashpit door 10.

When operating the device on the down draft principle, and the door 7 is open for firing, it is preferable to open the damper 25 thereby permitting any accumulated smoke above the coal bed to be carried off into the smoke box 26 through the opening 22.

Obviously, constructional modifications of the device are possible without departing from the spirit of the present invention and therefore it is to be understood that it is not necessary to limit the invention by the terms used in the foregoing description, excepting such as the state of the art may require.

What I claim isz- 1. A heating device comprising a re pot, a

combustion chamber beneath the fire pot, tubular grate bars between the nre pot and the combustion chamber, a vertically disposed air passageway leading from the grate bars at one end to the top of the fire pot, an ashpit beneath the combustion chamber, and a second passageway leading from the ashpit to the discharge iiue of the device.

2. A heating device comprising a fire pot having a series of transversely disposed hollow grate bars therein, a passageway leading from one end of said grate bars to the top of said iire pot, a smoke box above the nre pot, a combustion chamber beneath the grate bars, an ashpit beneath the combustion chamber, and a series of passageways extending from the ashpit to the smoke box.

3. A heating device comprising a re pot having a series of transversely disposed grate bars therein, an ashpit beneath the grate bars, a combustion chamber between the ashpit and the grate bars having a retaining shelf therein for catching fuel deposited from the grate bars, said re pot, combustion chamber, and ashpit being in communication, and a series of tubes extending from said ashpit having communication with the discharge flue of the device.

4. A heating device comprising a re pot having a series of transversely disposed hollow grate bars therein, a vertically disposed air passageway leading to the top of the re pot having communication at its lower end with said grate bars, a combustion chamber beneath the grate bars, an ashpit beneath the combustion chamber, a smoke box above the fire pot, and a series of passageways having communication with the ashpit and the smoke box.

5. A heating device comprising a re pot, a drum surrounding said re pot, a combustion chamber beneath the fire pot, tubular grate bars between the re pot and the combustion chamber extending to the outside of said drum, a vertically disposed air passageway leading from the grate bars at one end to the top of the lire pot, an ashpit beneath the combustion chamber, and a second passageway leading from the ashpit to the discharge flue of the device.

6. A heating device comprising a fire pot, a combustion chamber beneath the re pot, tubular grate bars between the re pot and the combustion chamber, a vertically disposed air passageway leading from the grate bars at one end into the top of the fire pot, a damper controlled discharge flue having communication with the upper end of the iire pot, a deflecting member depending `from the top of the i'ire pot cooperable with said passageway, and a second passageway active to draw products of combustion from the lower end of the combustion chamber, leading to said flue.

7. A heating device comprising a fire pot having anV apertured hollow grate, a vertical passageway leading into the top of the re pot having communication at its lower end with said grate, a combustion chamber beneath the grate, an ash pit beneath the combustion chamber, a smoke box above the firepot, and a series of passageways on opposing sides of the device having communication with the ash pit and the smoke box.

EDWIN F. EICHHORN. 

